Malaysia declared a state of emergency in the Serian district of Sarawak state on Friday after haze from forest fires in neighboring Indonesia drove air pollution to hazardous levels.

The Air Pollutant Index in Serian reached readings above 500, including peaks reported at 519 and 521, surpassing the threshold that triggers emergency measures. Malaysian authorities classify API levels above 300 as hazardous and above 500 as warranting an emergency declaration.

King Sultan Ibrahim consented to the declaration following advice from Prime Minister Anwar Ibrahim and Sarawak Premier Abang Johari Openg. The move applies only to the Serian district, which covers roughly 2,039 square kilometers, and enables stricter actions to protect public health.

Non-essential government and private offices, including plantations, construction sites, and quarries, will close. Schools across the district face closures, with some already shut earlier due to worsening conditions. Essential services such as supermarkets, petrol stations, and banks are expected to remain open.

The haze stems from fires in Indonesia's Kalimantan region on Borneo. Smoke has blanketed parts of Sarawak, prompting cloud-seeding operations that began on Thursday and will extend at least through Monday. Other areas in the state, including Kuching with a reading of 306, also recorded hazardous or very unhealthy air quality.

This marks a recurring seasonal challenge in Southeast Asia, where transboundary pollution affects Malaysia, Brunei, and Singapore. Authorities continue to monitor conditions and advise residents on protective measures, including the use of masks.